package sword2offer;

public class Offer010b {
    public int numWays(int n) {
        if (n==0)return 0;
        if (n==1)return 1;
        int []dp=new int[n+1];
        dp[0]=1;
        dp[1]=1;
        for (int i = 0; i < n+1; i++) {
            dp[i]=(dp[i-1]+dp[i-2])%1000000007;
        }
        return dp[n];
    }
}
